Atomic layer deposition (ALD) thin film deposition equipment having cleaning apparatus and cleaning method

ABSTRACT

An atomic layer deposition (ALD) thin film deposition equipment having a cleaning apparatus, this equipment including a reactor  100  in which a wafer is mounted and a thin film is deposited on the wafer, a first reaction gas supply portion  210  for supplying a first reaction gas to the reactor  100,  a second reaction gas supply portion  230  for supplying a second reaction gas to the reactor  100,  a first reaction gas supply line  220  for connecting the first reaction gas supply portion  210  to the reactor  100,  a second reaction gas supply line  240  for connecting the second reaction gas supply portion  230  to the reactor  100,  a first inert gas supply line  260  for supplying an inert gas from an inert gas supply source  250  to the first reaction gas supply line  220,  a second inert gas supply line  270  for supplying an inert gas from the inert gas supply source  250  to the second reaction gas supply line  240,  an exhaust line  400  for exhausting the gas within the rector  100  to the outside, and a cleaning gas supply line  340  connected to the first reaction gas supply line  220  for supplying a cleaning gas for cleaning the reactor  100.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to atomic layer deposition (ALD)thin film deposition equipment, and more particularly, to ALD thin filmdeposition equipment employing a cleaning apparatus and a cleaningmethod.

[0003] 2. Description of the Related Art

[0004] Thin film deposition equipment forms a predetermined thin film ona wafer by supplying reaction gases to the wafer received within areactor. This thin film deposition equipment includes chemical vapordeposition (CVD) thin film deposition equipment, atomic layer epitaxy(ALE) thin film deposition equipment, and others, and has been appliedto various fields for manufacturing semiconductor devices.

[0005] In thin film deposition equipment, a thin film is deposited notonly on a wafer by an introduced reaction gas, but a thin film orprocess byproduct can also be deposited on the inner wall or componentof a reactor, or on holes through which reaction gases are sprayed. Whenparticles separated from the thin film or process byproduct drop on awafer, the characteristics of a thin film deposited on the wafer aredeteriorated. This requires a cleaning apparatus and method ofeffectively removing a thin film or a process byproduct deposited on theinner wall, components or holes of a reactor.

SUMMARY OF THE INVENTION

[0006] An objective of the present invention is to provide an atomiclayer deposition (ALD) thin film deposition equipment having a cleaningapparatus, and a cleaning method thereof, by which a thin film orprocess byproduct deposited within a reactor or on the surface of itscomponent is effectively dry cleaned without opening the reactor, andthen a thin film deposition process can be easily performed.

[0007] To achieve the above objective, the present invention provides anatomic layer deposition (ALD) thin film deposition equipment having acleaning apparatus, this equipment including: a reactor 100 in which awafer is mounted and a thin film is deposited on the wafer; a firstreaction gas supply portion 210 for supplying a first reaction gas tothe reactor 100; a second reaction gas supply portion 230 for supplyinga second reaction gas to the reactor 100; a first reaction gas supplyline 220 for connecting the first reaction gas supply portion 210 to thereactor 100; a second reaction gas supply line 240 for connecting thesecond reaction gas supply portion 230 to the reactor 100; a first inertgas supply line 260 for supplying an inert gas from an inert gas supplysource 250 to the first reaction gas supply line 220; a second inert gassupply line 270 for supplying an inert gas from the inert gas supplysource 250 to the second reaction gas supply line 240; an exhaust line400 for exhausting the gas within the rector 100 to the outside; and acleaning gas supply line 340 connected to the first reaction gas supplyline 220 for supplying a cleaning gas for cleaning the reactor 100.Here, the cleaning gas is CIF₃.

[0008] Preferably, the cleaning gas supply line 340 includes: a cleaninggas mass flow controller (MFC) for controlling the flow of a suppliedcleaning gas; and at least one valve for allowing or blocking the flowof the cleaning gas. Also, preferably, the cleaning gas supply line 340further includes a filter for filtering out foreign materials existingwithin the cleaning gas.

[0009] To achieve the above objective, the present invention provides acleaning method for ALD thin film deposition equipment having a reactor100 including a reactor block 110 on which a wafer is mounted, a waferblock 140 installed within the reactor block 110, on which the wafer wis seated, and a diffusion plate having a plurality of spray holes 131formed over the wafer block 140 and a plurality of nozzles 133 slantedtoward the inner sidewall of the reactor block 110 to spray a gas towardthe edges of the wafer block 140. This cleaning method includes a maincleaning process performed in a state where no wafers are receivedwithin the reactor 100, for spraying a mixture of a cleaning gas and aninert gas onto the wafer w through the spray holes 131 and spraying aninert gas toward the edges of the wafer block 140 through the nozzles133.

[0010] Preferably, this cleaning method further includes a sub cleaningprocess performed in a state where no wafers are received within thereactor, for pulse-introducing the cleaning gas into the reactor 100 toinduce instantaneous diffusion due to a pressure fluctuation. Also,preferably, this cleaning method further includes a pre-coating processperformed in a state where no wafers are received within the reactor,for adhering fine particles remaining within the reactor to the insidesurface of the reactor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above objectives and advantages of the present invention willbecome more apparent by describing in detail preferred embodimentsthereof with reference to the attached drawings in which:

[0012]FIG. 1 is a schematic diagram of atomic layer deposition (ALD)thin film deposition equipment having a cleaning apparatus, according toa first embodiment of the present invention;

[0013]FIG. 2 is an exploded perspective view of a reactor in the ALDthin film deposition equipment of FIG. 1;

[0014]FIG. 3 is an exploded perspective view of a shower head and adiffusion plate in the reactor of FIG. 2;

[0015]FIG. 4 is a cross-sectional view of the reactor of FIG. 2;

[0016]FIG. 5 is a magnified cross-sectional view of the first mixingunit of the reactor of FIG. 4;

[0017]FIG. 6 is a graph showing the relationship between an interval (D)and a specific resistance while a thin film is formed;

[0018]FIG. 7 is a graph showing the relationship between the bottomtemperature of a diffusion plate and the speed of deposition of a TiNthin film when a TiN film is deposited using a TiCl₄ gas and an NH₃ gas;

[0019]FIG. 8 shows a reactor combined with a transfer module through avat valve;

[0020]FIG. 9 is a data showing the number of particles detected within areactor after a cleaning process;

[0021]FIG. 10 is a cross-sectional view of ALD thin film depositionequipment having a cleaning apparatus, according to a second embodimentof the present invention; and

[0022]FIG. 11 is a cross-sectional view of ALD thin film depositionequipment having a cleaning apparatus, according to a third embodimentof the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023]FIG. 1 shows atomic layer deposition (ALD) thin film depositionequipment having a cleaning apparatus, according to a first embodimentof the present invention. This ALD thin film deposition equipment candeposit a thin film, such as a TiN film or a TaN film, on a wafer.Deposition of a TiN thin film will now be described as an example. Inorder to form a TiN thin film, TiCl₄ is used as a first reaction gas,NH₃ is used as a second reaction gas, and Ar is used as an inert gas.

[0024] Referring to FIG. 1, ALD thin film deposition equipment includesa reactor 100 for receiving a wafer and depositing a thin film on thewafer, a gas jungle (this term was made by the present inventor todescribe complicatedly-connected lines) for supplying a reaction gas tothe reactor 100, and an exhaust line 400 for exhausting the gas withinthe reactor 100 to the outside.

[0025]FIG. 2 is an exploded perspective view of a reactor in the ALDthin film deposition equipment of FIG. 1. FIG. 3 is an explodedperspective view of the reactor of FIG. 2, in which a shower head plateis separated from a diffusion plate. FIG. 4 is a cross-sectional view ofthe reactor of FIG. 2, and FIG. 5 is a magnified cross-sectional view ofthe first mixing unit of the reactor of FIG. 4.

[0026] Referring to FIGS. 2, 3, 4 and 5, the reactor 100 includes areactor block 110 on which a wafer is placed, a shower head plate 120coupled to the reactor block 110 using hinges 128 and 129, a diffusionplate 130 installed on the shower head plate 120 for spraying a reactiongas and/or inert gas, and a wafer block 140 installed within the reactorblock 110, on which a wafer is seated. A first connection line 121 fortransferring a supplied first reaction gas and/or inert gas, and asecond connection line 122 for transferring a supplied second reactiongas and/or inert gas, are installed on the shower head plate 120.

[0027] First and second connection pipes 111 and 112 are installed onthe reactor block 110, and connected to first and second reaction gassupply lines 220 and 240, respectively, to be described later. The firstand second connection pipes 111 and 112 are connected to the first andsecond connection lines 121 and 122 installed on the shower head plate120 via a connecting portion 113 and an O-ring 113 a so that they aresealed.

[0028] At least two exhaust holes 117 and 118 for exhausting introducedinert gases and/or reaction gases are formed to be symmetrical to eachother on the bottom of the reactor block 110. A main O-ring 114 isinstalled on the upper surface of the reactor block 110, so that thereactor block 110 and the shower head plate 120 are securely sealed whenthe shower head plate 120 is covered.

[0029] The shower head plate 120 covers the reactor block 110, so that apredetermined pressure is constantly maintained within the reactor block110. Also, the shower head plate 120 covers the reactor block 110 sothat the diffusion plate 130 is placed within the reactor block 110.

[0030] The diffusion plate 130, which sprays a gas during a thin filmdeposition process, has a plurality of spray holes 131, which areconnected to the first connection line 121, and spray a first reactiongas and/or inert gas over the wafer block 140, and a plurality ofnozzles 133, which are connected to a passage 132 leading to the secondconnection line 122 and face the inner sidewall of the reactor block 110to spray a second reaction gas and/or inert gas onto the edges of thewafer block 140.

[0031] A first mixing portion 134 for evenly mixing a first reaction gasand an inert gas and flowing the mixture to the spray hole 131 is formedat the center of the inside of the diffusion plate 130, as shown inFIGS. 4 and 5. The first reaction gas and the inert gas flowing via theconnection line 121 are swirled and mixed, and then diffused and evenlysprayed onto the wafer via all of the spray holes 131.

[0032] Spray holes 131 are not formed below the first mixing portion 134in the diffusion plate 130. Preferably, the entire area of the diffusionplate 130 having the spray holes 131 is larger than the area of a waferw seated on the wafer block 140, so that a gas can be evenly spayed overthe entire surface of the wafer.

[0033] The nozzles 133 lead to the passages 132 radially formed from asecond mixing portion 135, and are slanted toward the inner sidewall ofthe reactor block 110, as shown in FIG. 4.

[0034] The second mixing portion 135 for evenly mixing a second reactiongas and an inert gas is formed between the second connection line 122and the shower head plate 120, as shown in FIG. 4. The second mixingportion 135 has a structure in which a hole 135 b is formed through apartition 135 a.

[0035] The wafer block 140, on which a wafer w is safely seated, has aheater H installed in the wafer block 140 to heat and maintain the waferblock 140 to a predetermined temperature during deposition.

[0036] The interval (D) between the diffusion plate 130 and the waferblock 140 is in the range of 20 mm to 50 mm. Referring to FIG. 6, whichis a graph showing the interval (D) and specific resistance duringdeposition of a thin film, it can be seen that the specific resistanceis the lowest when the interval (D) between the diffusion plate 130 andthe wafer block 140 is 30 mm. However, when other conditions, forexample, the types and amounts of first and second reaction gases, thetemperature of a wafer block, or the like, were changed, specificresistance values were low at the intervals D within a range of about 20to 50 mm, and it can be concluded that the interval D is an importantstructural property in forming an excellent thin film.

[0037] The interval within this range is compared to a conventionalchemical vapor deposition (CVD) reactor in which the interval between adiffraction plate to which a reaction gas is sprayed and a wafer blockon which a wafer is seated is about 50 to 100 mm. In the presentinvention, since the interval D is smaller than that in the prior art, adense first reaction gas layer is formed on a wafer w by the pressure ofa first reaction gas and/or inert gas sprayed from the spray holes 131.The first reaction gas layer reacts with a second reaction gas flowed inlater, so that a thin film having a higher purity and an excellentelectrical property can be formed.

[0038] A pumping baffle 150 is installed around the wafer block 140. Thepumping baffle 150 is made up of a sidewall 150 a installed on thelateral side of the wafer block 140, and a bottom wall 150 b throughwhich symmetrical holes 150 c are formed. A donut-shaped pumping pot 115connected to an exhaust line is formed below the bottom wall 150 b ofthe pumping baffle 150, that is, on the bottom of the reactor block 110.

[0039] The sidewall 150 a and the bottom wall 150 b of the pumpingbaffle 150 provide a space in which a second reaction gas and/or inertgas sprayed toward the inner sidewall of the reactor block 110 can moreevenly react to the first reaction gas layer formed on the wafer wseated on the wafer block 140. A process product generated duringdeposition of a thin film, and gases not used during deposition of athin film are slipped through the hole 150 c. These gases pass throughthe exhaust holes 117 and 118, and are exhausted via the pumping pot115.

[0040] When a thin film is deposited, the pressure within a reactor mustbe maintained to be 1 to 10 torr. In order to observe and control thispressure, a pressure measuring portion 160 must be installed within thereactor.

[0041] The above-described thin film deposition reactor has heaters (H)formed inside and outside to heat the reactor when a thin film isdeposited. For example, in a TiN thin film deposition process, when aTiN thin film is deposited, the temperature of the inner surface of thereactor block 110 must be kept at about 120 to 200° C., and thetemperature of the diffusion plate 130 must be kept at about 150 to 260°C. Also, the wafer block 140 must be kept at a temperature of about 425to 650° C., and the pumping baffle 150 must be kept at a temperature ofabout 150 to 230° C. The temperature of a vat valve 101 between thereactor 100 and a transfer module 102 for supplying and transferring awafer w must be maintained at about 140 to 170° C. Such a temperaturesetting can minimize formation of process byproducts.

[0042] A coolant passage 123 for allowing a coolant to flow is formed onthe shower head plate 120. The temperature of the diffusion plate 130can be lowered within a desired range by flowing a coolant such as oil,water or air through the coolant passage 123.

[0043] During a thin film deposition process, the inside temperature ofthe reactor 100 is important. When the inside temperature of the reactor100 departs an optimum temperature range, an excessive thin film orprocess byproduct is deposited on the surface of the diffusion plate130. Thus, many particles drop on the wafer, and the diffusion plate 130is eroded. Accordingly, the temperature of the diffusion plate 130 isalso an important variable, and this will now be described withreference to FIG. 7.

[0044]FIG. 7 is a graph showing the relationship between the bottomtemperature of the diffusion plate 130 and the speed of deposition of aTiN thin film, when a TiN film is deposited using a TiCl₄ gas and an NH₃gas. A graph when the bottom temperature of the diffusion plate 130 isT₁, and a graph when the bottom temperature of the diffusion plate 130is T₂, are shown in FIG. 7. Here, T₂ is greater than T₁. As shown in thegraph of FIG. 7, when the temperature of the diffusion plate 130 exceedsthe optimum temperature range, that is, when T₁<T₂, a greater amount ofTiCl₄ gas must be introduced into the reactor 100 to obtain the samedeposition speed of a TiN thin film, since a relatively greater amountof TiCl₄ gas are used to produce particles by reacting to the bottom ofthe diffusion plate 130 or to deposit a thin film on the diffusion plate130, instead of being used to deposit a thin film on a wafer w.Accordingly, the increased temperature of the diffusion plate 130 needsto be easily lowered as necessary. In this case, the temperature of thediffusion plate 130 can be reduced by allowing a coolant to flow to thecoolant passage 123 formed on the shower head plate 120. Consequently,during depositing a thin film, a thin film or process byproductdeposited on the bottom of a diffusion plate can be minimized byvoluntarily increasing or decreasing the temperature of the diffusionplate 130. Thus, particles and undesired influences upon the process canbe excluded, so finally a cleaning period can be increased, and acleaning effect can be improved.

[0045] The thin film deposition reactor having such a configuration iscombined with a transfer module 102 for supplying and transferring awafer w, having a vat valve 101 between them. The wafer w is transferredinto the reactor 100 via a wafer transfer hole 116 using a robot arm(not shown) and seated on the wafer block 140, as shown in FIG. 8.

[0046] As shown in FIG. 1, the gas jungle includes a first reaction gassupply portion 210 for supplying a reaction gas to the reactor 100, anda second reaction gas supply portion 230 for supplying a second gas tothe reaction gas 100. The first reaction gas supply portion 210 isconnected to the reactor 100 via a first reaction gas supply line 220,and the second reaction gas supply portion 230 is connected to thereactor 100 via a second reaction gas supply line 240. A first inert gassupply line 260 through which an inert gas supplied from the inert gassupply source 250 is transferred is connected to the first reaction gassupply line 220, and a second inert gas supply line 270 through which aninert gas supplied from the inert gas supply source 250 is transferredis connected to the second reaction gas supply line 240.

[0047] The first reaction gas supply portion 210 includes a bubbler 211for gasifying a first reaction material, a first reaction gas mass flowcontroller (MFC) 212 for controlling the flow of a first reaction gassupplied from the bubbler 211, and first and second valves V1 and V2installed on the line between the bubbler 211 and the first reaction gasMFC 212 for allowing or blocking the flow of a first reaction gas. Athird valve V3 for allowing or blocking the flow of the first reactiongas controlled by the first reaction gas MFC 212 is installed on thefirst reaction gas supply line 220.

[0048] The second reaction gas supply portion 230 includes a fourthvalve V4 for allowing or blocking the flow of a second reaction gas, anda second reaction gas MFC 232 for controlling the flow of a secondreaction gas passed through the fourth valve V4. A fifth valve V5 forallowing or blocking the flow of a second reaction gas controlled by thesecond reaction gas MFC 232 is installed on the second reaction gassupply line 240.

[0049] A sixth valve V6 for allowing or blocking the flow of a suppliedinert gas, a first inert gas MFC 262 for controlling the flow of aninert gas passed through the sixth valve V6, and a seventh valve V7 forallowing or blocking the flow of an inert gas controlled by the firstinert gas MFC 262, are installed on the first inert gas supply line 260.

[0050] An eighth valve V8 for allowing or blocking the flow of asupplied inert gas, a second inert gas MFC 272 for controlling the flowof an inert gas passed through the eighth valve V8, and a ninth valve V9for allowing or blocking the flow of an inert gas controlled by thesecond inert gas MFC 272, are installed on the second inert gas supplyline 270.

[0051] Here, the gas jungle includes a first bypass line 280 forallowing a first reaction gas and/or inert gas to flow directly to theexhaust line 400 without passing through the reactor 100, and a secondbypass line 290 for allowing a second reaction gas and/or inert gas toflow directly to the exhaust line 400 without passing through thereactor 100.

[0052] The first bypass line 280 has a tenth valve V10 connected to theline between the first reaction gas MFC 212 and the third valve V3 forallowing or blocking the flow of a first reaction gas to the exhaustline 400, and an eleventh valve V11 connected to the line between thefirst inert gas MFC 262 and the seventh valve V7 for allowing orblocking the flow of an inert gas to the exhaust line 400.

[0053] The second bypass line 290 has a twelfth valve V12 connected tothe line between the second reaction gas MFC 232 and the fifth valve V5for allowing or blocking the flow of a second reaction gas to theexhaust line 400, and a thirteenth valve V13 connected to the linebetween the second inert gas MFC 272 and the ninth valve V9 for allowingor blocking the flow of an inert gas to the exhaust line 400.

[0054] The first and second bypass lines 280 and 290 are adopted topurge the lines within the gas jungle, when a small amount of gas flowedin while a material of a first or second reaction gas or an inert gas isexchanged must flow directly to the exhaust line 400 without passing bythe reactor 100, when a contaminating source is generated within thelines, or when a new gas jungle is replaced. As described above, firstand second reaction gases, air or contaminating sources remaining withinlines are purged directly to the exhaust line 400 via the first andsecond bypass lines 280 and 290 by an inert gas, so that the reactor 100can be prevented from being contaminated. Thus, the first and secondbypass lines 280 and 290 are not used in processes for depositing a thinfilm, but used only in specific cases.

[0055] The gas jungle further includes a separate inert gas supply line320 for supplying an inert gas from the inert gas supply source 310 inorder to purge gases and/or contaminating sources remaining in thelines. The inert gas supply line 320 is organically connected to thefirst and second reaction gas supply portions 210 and 230, the first andsecond inert gas supply lines 260 and 270, the first and second bypasslines 280 and 290, and the exhaust line 400. The inert gas supply line320 is connected to gas lines fundamentally required by a process, via afourteenth valve V14 for allowing or blocking the flow of an inert gasto the first reaction gas supply portion 210, a fifteenth valve V15 forallowing or blocking the flow of an inert gas to the second reaction gassupply portion 230, a sixteenth valve V16 for allowing or blocking theflow of an inert gas to the first inert gas supply line 260, aseventeenth valve V17 for allowing or blocking the flow of an inert gasto the second inert gas supply line 270, an eighteenth valve V18 forallowing or blocking the flow of an inert gas to the first bypass line280, and a nineteenth valve V19 for allowing or blocking the flow of aninert gas to the second bypass line 290.

[0056] The reactor 100, the first and second bypass lines 280 and 290and a cleaning gas supply line 340 to be described later as a feature ofthe present invention are connected to the exhaust line 400. A throttlevalve TV controlled by the internal pressure of the reactor 100 measuredby the pressure measuring portion 160, for controlling the amount of anexhausted gas, is installed on the exhaust line 400. Twenty third,twenty fourth and twenty fifth valves V23, V24 and V25 for allowing orblocking the flow of an exhausted gas are also installed on the exhaustline 400. Her, the first bypass line 280 is connected to the linebetween the twenty third and twenty fourth valves V23 and V24, and thesecond bypass line 290 is connected to the line between the twenty fifthvalve V25 and the exhaust pump 410.

[0057] In this gas jungle, a cold spot due to undesired condensationoccurring when a reaction gas flows may be formed. Since a cold spotbadly affects the process for depositing a thin film, heaters (notshown) for preventing generation of a cold spot are installed on thelines. Preferably, the heaters are independently installed at as manyareas as possible along lines, and a temperature gradient is formedalong a line. In this embodiment, the temperature gradient isestablished to be within a range of 40 to 200° C. toward the reactor100.

[0058] The gas jungle further includes a cleaning gas supply line 340for cleaning the reactor 100. The cleaning gas supply line 340 isconnected to the first reaction gas supply line 220, and includes acleaning gas supply portion 330 for supplying a cleaning gas, a twentyfirst valve V21 for allowing or blocking the flow of a supplied cleaninggas, a cleaning gas MFC 342 for controlling the flow of a cleaning gaswhich has passed through the twenty first valve V21, and a twenty secondvalve V22 for allowing or blocking the flow of a cleaning gas which hasbeen controlled by the cleaning gas MFC 342. Here, a filter 332 forfiltering out foreign materials existing within a cleaning gas isinstalled on the line between the cleaning gas supply portion 330 andthe twenty first valve V21. In the above-described structure, a CIF₃ gascan be used as a cleaning gas.

[0059] Here, the cleaning gas supply line 340 is connected to the twentysixth valve V26 and the second bypass line 290 connected to the exhaustline 400, in order to allow a cleaning gas to flow directly to theexhaust line 400 without passing through the reactor 100. A cleaning gasintroduced via the cleaning gas supply line 340 is exhausted to theoutside via the second bypass line 290 and the exhaust line 400, whenthe twenty second valve V22 is closed and the twenty sixth valve V26 isopened.

[0060] The operation of the first embodiment of ALD thin film depositionequipment having a cleaning apparatus with such a structure will now bedescribed. This embodiment refers to a structure for depositing a TiNthin film on a wafer. To achieve this embodiment, TiCl₄ is used as afirst reaction gas, NH₃ is used as a second reaction gas, and Ar is usedas an inert gas. Thus, liquid TiCl₄ is contained in the bubbler 211.

[0061] The wafer w is transferred into the reactor 100 via the wafertransfer hole 116 using the robot arm (not shown) of the transfer module102, and seated on the wafer block 140.

[0062] When the wafer w is seated on the wafer block 140, thetemperature of the wafer block 140 increases within a range of 425 to650° C., so that the temperature of the wafer w is increased to 400 to600° C. After the wafer temperature is stabilized, the step ofintroducing a gas into the reactor 100 is performed.

[0063] The gas introducing step starts by opening the first valve V1,the sixth valve V6, the eighth valve V8, and the fourth valve V4 forseveral seconds. Then, a bubbled TiCl₄ gas is filled up to the secondvalve V2, and Ar gas is filled up to the seventh and ninth valves V7 andV9 after its amount is appropriately controlled by the first and secondinert gas MFCs 262 and 272. An NH₃ gas is filled up to the fifth valveV5 after its amount is appropriately controlled by the second reactiongas MFC 232.

[0064] Next, an Ar gas is flowed into the reactor 100 through theseventh and ninth valves V7 and V9. Before the Ar gas is introduced, theinternal pressure of the reactor 100 is kept at 10⁻⁴˜5×10⁻³ torr.However, as the Ar gas is introduced, the internal pressure of thereactor 100 is 1 to 10 torr. This pressure is obtained by the pressuremeasuring portion 160 installed in the reactor 100 appropriately openingthe throttle valve TV of the exhaust line 400. Here, the reason why theseventh and ninth valves V7 and V9 are opened after the sixth and eighthvalves V6 and V8 are opened is that the gas within the reactor 100 mayflow backward through the seventh and ninth valves V7 and V9 when theyare suddenly opened.

[0065] Thereafter, a TiN thin film is deposited on a wafer w byalternately introducing a TiCl₄ gas and an NH₃ gas into the reactor 100.For example, when a TiCl₄ gas is introduced first, a TiCl₄ gas and an Argas are first introduced into the reactor, in the first step. After apredetermined period of time, the TiCl₄ gas is excluded. Thus, a TiCl₄layer is formed on the wafer w, and compressed by an Ar gas which iscontinuously introduced.

[0066] In the second step, an NH₃ gas and an Ar gas are introducedtogether. The supply of the NH₃ gas is blocked for a predeterminedperiod of time. The NH₃ gas reacts to the TiCl₄ layer previously formedon the wafer w, thereby forming the TiN thin film on the wafer w. Thatis, a TiN+NH₃ layer is formed by the consecutive first and second steps.

[0067] Next, the first step is again performed to continuously grow athin film on the TiN+NH₃ layer. Then, the TiN+NH₃ layer is changed to aTiN+TiN+TiCl₄ layer. Thereafter, the second step is performed to form aTiN+TiN+TiN+NH₃ layer. A TiN thin film having a desired thickness can beobtained by repeating this process.

[0068] This TiN thin film deposition process is performed by alternatelyopening and closing the third and fifth valves V3 and V5 in a statewhere the first and fourth valves V1 and V4 are always open, while an Argas is continuously introduced into the reactor 100 by opening thesixth, seventh, eighth and ninth valves V6, V7, V8 and V9.

[0069] Here, the second valve V2 is opened before the third valve V3, sothat a TiCl₄ gas passes through the first reaction gas MFC 212 and isfilled up to the third valve V3. Thereafter, when the third valve V3 isopened to send a first reaction gas to the reactor 100, the second valveV2 is closed. That is, the first reaction gas flows to the firstreaction gas supply line 220 by sequentially passing through valves. Aprocess byproduct gas generated during reaction is exhausted via thethrottle valve TV of the exhaust line 400, and the twenty third, twentyfourth and twenty fifth valves V23, V24 and V25.

[0070] To sum up the above-described reaction, a TiCl₄ gas flows to thefirst reaction gas supply line 220 via the third valve V3 after its flowis controlled by the first and second valves V1 and V2, and an Ar gas iscontrolled in its flow, passes through the seventh valve V7, is mixedwith the TiCl₄ gas on the first reaction gas supply line 220, and flowsto the reactor 100.

[0071] Thereafter, a mixture of TiCl₄ and Ar pass through the firstconnection pipe 111 and the first connection line 121, is evenly mixedonce more in the first mixing portion 134, and is evenly sprayed overthe wafer w through the spray holes 131. An NH₃ reaction gas iscontrolled in its flow through the fourth valve V4, and then flows tothe second reaction gas supply line 240 via the fifth valve V5. An Argas is controlled in its flow, passes through the ninth valve V9, ismixed with an NH₃ gas on the second reaction gas supply line 240, andthen flows to the reactor 100. Next, a mixture of NH₃ and Ar passthrough the second connection pipe 112 and the second connection line122, is evenly mixed once more in the second mixing portion 135, and issprayed toward the inner sidewall of the reactor block 110 through thenozzles 133.

[0072] Here, it is preferable that the flow of a TiCl₄ gas is 1 SCCM ormore, the flow of an Ar gas to be mixed with a TiCl₄ gas is 50 SCCM ormore, the flow of NH₃ is 50 SCCM or more, and the flow of an Ar gas tobe mixed with an NH₃ gas is 60 SCCM or more. These values are obtainedby several experiments. When the flow rates are at least as describedabove, a thin film having a high purity, an excellent electricalproperty, and a good step coverage can be obtained.

[0073] This thin film deposition is achieved by consecutive gas sprayingto the reactor 100, and the process pressure of the reactor is keptconstant by an appropriate signal exchange and control between apressure measuring portion and valves including a throttle valve.Therefore, the uniformity of a deposited thin film is improved.

[0074] Also, when a compound gas containing Ta is used as a firstreaction gas, and a compound gas containing N, for example, an NH₃ gas,is used as a second reaction gas, a TaN thin film can be deposited on awafer by the method described above.

[0075] Here, an inert gas such as the Ar gas adequately dilutes thefirst and second reaction gases and smoothly sends the diluted gases tothe reactor 100, so this acts as an important process variable. Also,the inert gas prevents a gas from flowing backward to a correspondingreaction gas supply line, since more than a predetermined amount ofinert gas always flows to the first and second reaction gas supply lines220 and 240 during, before and after a thin film is deposited on awafer.

[0076] Hereinafter, a cleaning method according to the present inventionwill be described. The cleaning method includes a main cleaning processand a sub cleaning process for removing a thin film or process byproductfrom the inner wall and components of the reactor 100 using a flowingcleaning gas and inert gas, and a pre-coating process for attachingparticles remaining within the reactor 100 to the inner wall andcomponents of the reactor.

[0077] The main cleaning process, which is performed in a state where nowafers w is received by the reactor 100, is performed in a predeterminedcycle or when the number of particles produced by excessive depositionof a thin film or process byproduct (powder, a thin film containingimpurities, etc.) on the inner wall of the reactor 100 or severalcomponents (for example, a wafer block, the sidewall 150 a of a pumpingbaffle, etc.) exceeds a predetermined value. The cleaning cycle variesaccording to the type of a formed thin film. However, when a TiN, Ti orTiAlN thin film is deposited, the main cleaning process is performedafter at least 500 wafers are deposited.

[0078] In the main cleaning process, a cleaning gas controlled in itsflow by the cleaning gas MFC 342, and an inert gas controlled in itsflow by the first inert gas MFC 262 are mixed in the first reaction gassupply lines 220, and sprayed onto the wafer block 140 through the sprayholes 131 of the diffusion plate 130, and an inert gas controlled in itsflow by the second inert gas MFC 272 is sprayed to the edges of thewafer block 140 through the second reaction gas supply line 240 and thenozzles 133 of the diffusion plate 130. In this embodiment, a CIF₃ gasis used as a cleaning gas, and an Ar gas is used as an inert gas.

[0079] A CIF₃ gas is nearly colorless transparent at room temperature,and has a boiling point of 11.75° C. The CIF₃ gas must not be liquefieduntil it is introduced into the reactor 100, and heaters must beinstalled along lines to apply an appropriate temperature to the gas.

[0080] An Ar gas adequately dilutes a CIF₃ gas by allowing the CIF₃ gasto flow to the diffusion plate 130 via the first reaction gas supplyline 220, and allows the CIF₃ gas to smoothly flow into the reactor 100.

[0081] Upon the main cleaning process, the inside of the reactor must beset to a temperature which prevents damage to the material of thereactor due to excessive etching. Most of the components of the reactorare stable to a CIF₃ gas when they have a surface temperature of 170° C.or less, and it is proper that the temperature of an exhaust line isalso 170° C. or less. Accordingly, heaters are controlled so that thesurface temperature of the components of the reactor 100 except for thewafer block 140 does not exceed 200° C., preferably, is at 170° C. orless. Also, the main cleaning process is performed when the thin filmdeposition process temperature (425 to 650° C.) of the wafer block 140is lowered to about 300° C.

[0082] Here, preferably, the flow of the CIF₃ gas is controlled to 50SCCM or greater, the flow of an Ar gas, which is mixed with the CIF₃gas, and flows to the spray holes 131, is controlled to 50 SCCM orgreater, and an Ar gas flowing to the nozzles 133 via the secondreaction gas supply line 240 is controlled to 300 SCCM or greater. It ispreferable that the inside pressure of the reactor 100 is set to a rangeof 0.5 to 10 torr. This gas cleaning process requires about 50 to 90minutes.

[0083] The sub cleaning process, which is performed in a state where thereactor 100 receives no wafers, is more simplified than the maincleaning process which is performed when the number of particlesproduced by local excessive deposition within the reactor 100 although asufficient amount of process byproduct is not deposited within thereactor 100 exceeds a predetermined number.

[0084] The sub cleaning process denotes pulse introduction in which aCIF₃ gas is introduced into the reactor 100 by periodically opening andclosing the twenty second valve V22. When the twenty second valve V22 isperiodically opened and closed, a CIF₃ gas causes a pressure fluctuationwithin the reactor 100, and etches out a thin film or process byproductsexcessively deposited on local areas within the reactor 100 while beinginstantaneously evenly diffused due to the pressure fluctuation whenbeing introduced into the reactor.

[0085] Here, the flow rate of the CIF₃ gas is controlled to 50 SCCM orhigher, the flow rate of an Ar gas, which is mixed with the CIF₃ gas andflows to the spray holes 131, is controlled to 50 SCCM or higher, andthe flow rate of an Ar gas, which is mixed with the CIF₃ gas in thesecond reaction gas supply line 240 and flows to the nozzles 133, iscontrolled to 300 SCCM or higher.

[0086] In the pulse introduction process, while an Ar gas iscontinuously sprayed through the nozzles 133, a CIF₃ gas is introducedinto the reactor 100 by periodically opening/closing the twenty secondvalve V22. The opening/closing period of the twenty second valve V22 isset to be about 1 to 2 seconds, and the total pulse introducing time isset to be about 5 minutes or more. Here, the inside pressure of thereactor 100 is set to be within a range of 0.5 to 10 torr. Also, thetemperature of the wafer block 140 is set to be about 400° C. or less,and the temperatures of the components of the reactor 100 except for thewafer block 140 are set to be at most 200° C., preferably, at 170° C. orless.

[0087] In these main and sub cleaning processes, when a constant amountof a CIF₃ gas flows into the reactor 100 and the inside pressure of thereactor 100 is not variable, it is preferable that the sum of the amountof an Ar gas sprayed through the spray holes 131 and an Ar gas sprayedthrough the nozzles 133 is made constant in order to make the averageetching speed of a thin film deposited on the entire inside surface ofthe reactor 100 uniform.

[0088] The pre-coating process is performed in a state where the reactor100 receives no wafers, and adheres fine particles, which remain withinthe reactor 100 after the main cleaning process using a CIF₃ gas, to theinside surface of the reactor 100. This process prevents particles fromdropping over a wafer during depositing a thin film.

[0089] The gases within the reactor 100 must be sufficiently exhaustedbefore the pre-coating process is performed. In order to achieve this,after the main cleaning process or sub cleaning process is completed,pumping is performed as much as possible by 100% opening the throttlevalve TV while introduction of all gases into the reactor 100 isstopped, thereby rapidly exhausting remaining CIF₃ gas and Ar gas withinthe reactor 100 and remaining process byproducts to the exhaust line400.

[0090] When the inside of the reactor 100 is sufficiently in a vacuumstate, the temperature of the wafer block 140, which has dropped duringthe main cleaning process, starts being increased to the thin filmdeposition process temperature of about 425 to 650° C. While thetemperature of the wafer block 140 is increased, flushing forintroducing an Ar gas into the reactor 100 is performed at the sametime. Flushing is performed by opening the sixth and seventh valves V6and V7 to allow an Ar gas to flow into the reactor 100 via the firstreaction gas supply line 220 and simultaneously opening the eighth andninth valves V8 and V9 to allow an Ar gas to flow into the reactor 100via the second reaction gas supply line 240.

[0091] While the flushing is carried out, the temperature of the waferblock 140 increases up to the thin film deposition process temperature.When the temperature of the wafer block 140 is stabilized at the thinfilm deposition process temperature, the pre-coating process, which issimilar to the thin film deposition process, is performed.

[0092] The pre-coating process is performed by mixing a flow-controlledTiCl₄ gas and an Ar gas and spraying onto the wafer block 140 throughthe spray holes 131, and mixing an NH₃ gas and a flow-controlled Ar gasand spraying toward the edges of the wafer block 140 through the nozzles133.

[0093] Here, it is important to introduce an NH₃ gas at least severalseconds before a TiCl₄ gas is introduced into the reactor, since a TiCl₄gas is strongly erosive. If a TiCl₄ gas is first introduced into thereactor 100, it instantaneously etches the internal components of thereactor to thus generate very tiny solid particles. Thus, an NH₃ gas isintroduced at least several seconds before a TiCl₄ gas is introduced, inorder to pre-exist an NH₃ gas layer on the inside surface of the reactor100, so that a TiCl₄ gas introduced reacts to the NH₃ gas. Therefore,etching is minimized. That is, when a compound gas containing Cl is usedas the first reaction gas, and an NH₃ gas is used as the second reactiongas, the NH₃ gas is introduced at least several seconds before the firstreaction gas is introduced into the reaction gas, in order to minimizegeneration of particles.

[0094] Thereafter, the first step of mixing and introducing the TiCl₄gas and an Ar gas into the reactor 100 and excluding the TiCl₄ gas for apredetermined period of time, and the second step of introducing an NH₃gas and an Ar gas into the reactor 100 and excluding the NH₃ gas for apredetermined period of time, are alternately repeated. Alternatively,the first step of mixing and introducing a TiCl₄ gas and an Ar gas andexcluding the TiCl₄ gas for a predetermined period of time, while theNH₃ gas and an inert gas are continuously introduced, is repeated. Inthis way, the pre-coating process is achieved.

[0095] The pre-coating process is very similar to a thin film depositionprocess, except that it is performed in a state where no wafers aremounted within the reactor 100. Also, the pre-coating process is verysimilar to a thin film deposition process in terms of depositionconditions. That is, as in a thin film deposition process, when acompound gas containing a transfer metal element such as Ti, Ta or W isused as a first reaction gas, and an NH₃ gas is used as a secondreaction gas, the temperature of the wafer w during thin film depositionis maintained at 400 to 600° C., and the temperature of lines connectedto the reactor 100 is maintained at 40 to 200° C.

[0096] Data of an experiment based on the thin film deposition equipmenthaving such a structure is shown in FIG. 9. FIG. 9 shows the number ofparticles detected within a reactor before and after a cleaning process.In FIG. 9, reference character A denotes the number of particlesdetected after thin films are deposited on 500 wafers, referencecharacter B denotes the number of particles detected after the maincleaning process, and reference character C denotes the number ofparticles detected after the pre-coating process. In this embodiment, 28particles were detected after thin films are continuously deposited on500 wafers, 275 particles were detected after a 60-minute cleaningprocess, and 15 particles were detected after a 10 minute pre-coatingprocess. Here, the detection of 275 particles after the cleaning processshows not that the inside of the reactor 100 is contaminated, but thatcleaning process byproducts existing within a diffusion plate duringcleaning remain by failing to slipping to an exhaust line and drop overthe wafer w. Thereafter, if the pre-coating process is performed, thenumber of particles detected can be significantly reduced.

[0097] The above-described cleaning process is different from aconventional wet cleaning process, which is performed in a state where areactor is opened, and can minimize a time loss caused during the wetcleaning process. In this embodiment, the cleaning process can beperformed at least five to ten times in a cycle of about 500 wafers ormore.

[0098] A second embodiment of ALD thin film deposition equipment havinga cleaning apparatus according to the present invention will now bedescribed with reference to FIG. 10. The same reference numerals asthose in FIG. 1 denote the same elements.

[0099] In contrast to the first embodiment in which a TiN or TaN thinfilm can be deposited on a wafer, a thin film such as a WN thin film canbe formed in the second embodiment. In order to achieve the secondembodiment, the first reaction gas supply portion 210 in the firstembodiment is replaced with a first reaction gas supply portion 510. Thefirst reaction gas supply portion 510 includes a thirty first valve V31of allowing or blocking the flow of a first reaction gas, and a firstreaction gas MFC 512 for controlling the flow of a first reaction gaswhich has passed through the thirty first valve V31. The first reactiongas supply portion 510 is connected to the third valve V3.

[0100] That is, in this structure, when a WN thin film is formed, WF6 isused as the material of a first reaction gas, a compound gas containingN, for example, an NH₃ gas, is used as a second reaction gas, and an Argas is used as an inert gas. The WN thin film deposition method usingthe above-mentioned gases is almost the same as a TiN deposition method,so it will not be described in detail.

[0101] A third embodiment of ALD thin film deposition equipment having acleaning apparatus according to the present invention will now bedescribed with reference to FIG. 11. The same reference numerals asthose in FIG. 1 denote the same elements.

[0102] In contrast to the first embodiment in which a TiN or TaN thinfilm can be deposited on a wafer, a thin film such as a Ti or TiAlN filmas well as a TiN or TaN film can be formed in the third embodiment. Inorder to achieve this, the third embodiment further includes a thirdreaction gas transfer line for transferring a third reaction gasTriMethylAluminum (TMA) and a fourth reaction gas transfer line fortransferring a fourth reaction gas H₂.

[0103] A fourth reaction gas supply portion 610 includes a thirty secondvalve V32 for allowing or blocking the flow of supplied H2, a fourthreaction gas MFC 612 for controlling the flow of H2 which has passedthrough the thirty second valve V32, and a thirty third valve V33 forallowing or blocking the flow of H2 controlled by the fourth reactiongas MFC 612.

[0104] A third reaction gas supply portion 620 includes a bubbler 621for gasifying a third reaction material, a third reaction gas MFC 622for controlling the flow of a third reaction gas, a thirty fourth valveV34 installed on the line between the bubbler 621 and the third reactiongas MFC 622 for allowing or blocking the flow of the third reaction gas,and a thirty fifth valve V35 for allowing or blocking the flow of thethird reaction gas, which has been controlled by the third reaction gasMFC 622, to the second reaction gas supply line 240.

[0105] That is, in this structure, in order to form a thin film such asa Ti or TiAlN thin film as well as a TiN or TaN thin film, a compoundgas containing a transfer metal element Ti or Ta is used as a firstreaction gas, an Ar gas is used as an inert gas, a compound gascontaining N is used as a second gas, a TMA gas is used as a thirdreaction gas, and an H₂ gas is used as a fourth reaction gas.

[0106] The third embodiment of the thin film deposition apparatus havingsuch a configuration is almost the same as the first embodiment, so itwill not be described in detail.

[0107] In all of the embodiments described above, Ti, TiN, TiAlN, WN andTaN thin films are mentioned as an ALD thin film. These embodiments arerepresentative of the present invention. Thus, the present invention canalso be applied when an ALD thin film containing a transfer metalelement such as WSIN, TiSiN or TaSiN is deposited using changed reactiongases.

[0108] In a cleaning apparatus and method in ALD thin film depositionequipment according to the present invention, a thin film or processbyproducts deposited within a reactor or on the surfaces of componentsof the reactor are effectively dry-cleaned without opening the reactor.Thus, a thin film deposition process can be easily performed aftercleaning.

[0109] Also, when a thin film such as Ti, TiAlN, TiN, TaN, WN, WSIN,TiSiN or TaSiN thin film is formed, a thin film and process byproductscan be effectively removed from the inner wall or components of areactor during a cleaning process, after a thin film deposition process.

What is claimed is:
 1. Atomic layer deposition (ALD) thin filmdeposition equipment including a cleaning apparatus, comprising: areactor 100 in which a wafer is mounted and a thin film is deposited onthe wafer; a first reaction gas supply portion 210 for supplying a firstreaction gas to the reactor 100; a second reaction gas supply portion230 for supplying a second reaction gas to the reactor 100; a firstreaction gas supply line 220 for connecting the first reaction gassupply portion 210 to the reactor 100; a second reaction gas supply line240 for connecting the second reaction gas supply portion 230 to thereactor 100; a first inert gas supply line 260 for supplying an inertgas from an inert gas supply source 250 to the first reaction gas supplyline 220; a second inert gas supply line 270 for supplying an inert gasfrom the inert gas supply source 250 to the second reaction gas supplyline 240; an exhaust line 400 for exhausting the gas within the rector100 to the outside; and a cleaning gas supply line 340 connected to thefirst reaction gas supply line 220 for supplying a cleaning gas forcleaning the reactor
 100. 2. The ALD thin film deposition equipment ofclaim 1, wherein the cleaning gas is CIF₃.
 3. The ALD thin filmdeposition equipment of claim 1, wherein the cleaning gas supply line340 comprises: a cleaning gas mass flow controller (MFC) for controllingthe flow of a supplied cleaning gas; and at least one valve for allowingor blocking the flow of the cleaning gas.
 4. The ALD thin filmdeposition equipment of claim 3, wherein the cleaning gas is CIF₃. 5.The ALD thin film deposition equipment of claim 3, wherein the cleaninggas supply line 340 further comprises a filter for filtering out foreignmaterials existing within the cleaning gas.
 6. The ALD thin filmdeposition equipment of claim 1, wherein the first reaction gas supplyportion 210 comprises: a bubbler 211 for gasifying a first reactionmaterial; a first reaction gas mass flow controller (MFC) 212 forcontrolling the flow of a first reaction gas supplied from the bubbler211; and a first valve V1 installed on the line between the bubbler 211and the first reaction gas MFC 212 for allowing or blocking the flow ofthe first reaction gas.
 7. The ALD thin film deposition equipment ofclaim 6, wherein the first reaction gas is a TiCl₄ gas or a compound gascontaining Ta, and the second reaction gas is NH₃.
 8. The ALD thin filmdeposition equipment of claim 1, wherein a first reaction gas supplyportion 510 comprises: a thirty first valve V31 for allowing or blockingthe flow of a first reaction gas supplied; and a first reaction gas MFC512 for controlling the flow of a second reaction gas which has passedthrough the thirty first valve V31.
 9. The ALD thin film depositionequipment of claim 8, wherein the first reaction gas is WF₆, and thesecond reaction gas is NH₃.
 10. The ALD thin film deposition equipmentof claim 1, further comprising: a third reaction supply portion 620 forsupplying a third reaction gas to the second reaction gas supply line240; and a fourth reaction supply portion 610 for supplying a fourthreaction gas to the second reaction gas supply line 240, wherein thefourth reaction gas supply portion 610 has a thirty second valve V32 forallowing or blocking the flow of a fourth reaction gas supplied, afourth reaction gas MFC 612 for controlling the flow of a fourth gaswhich has passed through the thirty second valve V32, and a thirty thirdvalve V33 for allowing or blocking the flow of a fourth gas which hasbeen controlled by the fourth reaction gas MFC
 612. 11. The ALD thinfilm deposition equipment of claim 10, wherein the third reaction gassupply portion 620 comprises: a bubbler 621 for gasifying a thirdreaction material; a third reaction gas MFC 622 for controlling the flowof the third reaction gas supplied from the bubbler 621; a thirty fourthvalve V34 installed on the line between the bubbler 621 and the thirdreaction gas MFC 622 for allowing or blocking the flow of the thirdreaction gas; and a thirty fifth valve V35 for allowing or blocking theflow of the third reaction gas, which has been controlled by the thirdreaction gas MFC 622, to the second reaction gas supply line
 240. 12.The ALD thin film deposition equipment of claim 10, wherein the firstreaction gas is a compound gas containing a transfer metal element suchas Ti, Ta or W, the second reaction gas is NH₃, the third reaction gasis TriMethylAluminum (TMA), and the fourth reaction gas is H₂.
 13. TheALD thin film deposition equipment of claim 1, wherein the reactor 100comprises: a reactor block 110 on which a wafer is mounted; a showerhead plate 120 for maintaining a predetermined pressure constant bycovering the reactor block 110; a diffusion plate installed on thebottom of the shower head plate 120, the diffusion plate having aplurality of spray holes 131 formed over the wafer w to spray a firstreaction gas and/or inert gas transferred via the first reaction gassupply line 220 onto the upper surface of the wafer w, and a pluralityof nozzles 133 slanted toward the inner sidewall of the reactor block110 to spray a second reaction gas and/or inert gas transferred via thesecond reaction gas supply line 240; and a wafer block 140 installedwithin the reactor block 110, on which the wafer w is seated.
 14. TheALD thin film deposition equipment of claim 13, wherein a coolantpassage 123 is formed in the shower head plate 120 in order to decreasethe temperature of the diffusion plate 130 to a desired temperaturerange.
 15. A cleaning method for ALD thin film deposition equipmenthaving a reactor 100 including a reactor block 110 on which a wafer ismounted, a wafer block 140 installed within the reactor block 110, onwhich the wafer w is seated, and a diffusion plate having a plurality ofspray holes 131 formed over the wafer block 140 and a plurality ofnozzles 133 slanted toward the inner sidewall of the reactor block 110to spray a gas toward the edges of the wafer block 140, the cleaningmethod comprising a main cleaning process performed in a state where nowafers are received within the reactor 100, for spraying a mixture of acleaning gas and an inert gas onto the wafer w through the spray holes131 and spraying an inert gas toward the edges of the wafer block 140through the nozzles
 133. 16. The cleaning method of claim 15, wherein,in the main cleaning process, a cleaning gas flows at 50 SCCM or higher,an inert gas is mixed with the cleaning gas and flows to the spray holes131 at 50 SCCM or higher, and an inert gas flows to the nozzles 133 at300 SCCM or higher.
 17. The cleaning method of claim 16, wherein, in themain cleaning process, the inside pressure of the reactor 100 is set tobe 0.5 to 10 torr.
 18. The cleaning method of claim 16, wherein, in themain cleaning process, the inside surface temperature of the reactor 100except for the wafer block 140 is set to be 200° C. or less.
 19. Thecleaning method of claim 15, further comprising a sub cleaning processperformed in a state where no wafers are received within the reactor,for pulse-introducing the cleaning gas into the reactor 100 to induceinstantaneous diffusion due to a pressure fluctuation.
 20. The cleaningmethod of claim 19, wherein, in the sub cleaning process, a cleaning gasflows at 50 SCCM or higher, an inert gas is mixed with the cleaning gasand flows to the spray holes 131 at 50 SCCM or higher, and an inert gasflows to the nozzles 133 at 300 SCCM or higher.
 21. The cleaning methodof claim 19, wherein, in the sub cleaning process, the inside pressureof the reactor 100 is set to be 0.5 to 10 torr.
 22. The cleaning methodof claim 19, wherein, in the sub cleaning process, the inside surfacetemperature of the reactor 100 except for the wafer block 140 is set tobe 200° C. or less.
 23. The cleaning method of claim 15, furthercomprising a pre-coating process performed in a state where no wafersare received within the reactor, for adhering fine particles remainingwithin the reactor to the inside surface of the reactor.
 24. Thecleaning method of claim 23, wherein the pre-coating process isperformed by mixing the first reaction gas and the inert gas andspraying the gas mixture onto the wafer block through the spray holes131, and mixing the second reaction gas and the inert gas and sprayingthe gas mixture toward the edges of the wafer block through the nozzles133.
 25. The cleaning method of claim 23, wherein the pre-coatingprocess is performed by repeating a first step of mixing and introducingthe first reaction gas and the inert gas and excluding the firstreaction gas for a predetermined period of time, and a second step ofintroducing the second reaction gas and the inert gas into the reactor100 and excluding the second reaction gas for a predetermined period oftime.
 26. The cleaning method of claim 23, wherein the pre-coatingprocess is performed by repeating a first step of mixing and introducingthe first reaction gas and the inert gas and excluding the firstreaction gas for a predetermined period of time, while the secondreaction gas and the inert gas are continuously introduced into thereactor
 100. 27. The cleaning method of claim 23, wherein in thepre-coating process, an NH₃ gas is introduced into the reactor 100 atleast several seconds before a first reaction gas is introduced into thereactor 100, when a compound gas containing Cl is used as the firstreaction gas, and the NH₃ gas is used as the second reaction gas. 28.The cleaning method of claim 15, wherein the cleaning gas is CIF₃.